Numerical Simulation on Chain Dynamic of Polymer Solution in Microchannels: A Dissipative Particle Dynamics Study

The chain dynamics and the rheological property of the polymer solution in the microscale confined space (e.g., microchannel) are complex and still unclear. In this paper, based on the prior research work, a dissipative particle dynamics (DPD) method is established to systematically simulate the dynamic behavior of polymer chains and the properties of the polymer solution in microchannels by combining the modified FENE chain model and a new boundary condition setting, especially for the gradually contracted microchannel. It is found that the concentration of the polymer chain, the degree of constraint, and the Reynolds number influence the dynamic behavior of the polymer chain by changing the constraint effect or the hydrodynamic effect. In addition, the geometrical structure of the microchannel significantly changes the dynamic behavior of the polymer chain. The chain dynamics in the gradually contracted microchannel are quite different from that in the straight microchannel. Finally, the rheological characteristics of the power-law fluid and the lateral migration of the solid particle in the viscoelastic fluid in the microchannel are also simulated, and the simulation results are in good agreement with the result reported in the literature, which further verifies the accuracy of the present simulation method.